Crew transport vehicles and other vehicles that remain in Earth orbit for extended periods require thrust-vectorable rocket motor nozzles capable of interpulse storage (i.e., intermittent ignitions of the motor between periods of non-use). Such multi-pulse operation subjects the motor nozzle to extreme high temperatures during operation of the motor and extreme low temperatures during non-use in space (e.g., more than 100 km above the Earth's surface). Conventional thrust-vectorable rocket motor nozzles may include structural components configured to withstand the loads applied by high gas pressures within the nozzle, and insulating components configured to protect the structural components from melting, charring, or degrading under the flow of hot gas exiting the motor. The structural components may be made from metal alloys (e.g., titanium alloys), and the insulating components may be made from composite materials such as woven carbon or silica fibers in a cured resin (e.g., phenolic) matrix. The insulating components are typically bonded to the structural components with epoxy adhesives.
The extreme temperature cycles to which a rocket motor nozzle is exposed during multi-pulse use can quickly cause failure of the epoxy adhesives. Such adhesives may begin to degrade and potentially debond at temperatures above about 400° F. Furthermore, any difference in thermal expansion rates between the structural components and the insulating components is amplified by the temperature extremes to which the nozzles are subjected, and may further contribute to debonding of the adhesive. Debonding and degradation of the adhesives may expose the metal structural components to the flow of hot gas exiting the rocket motor, which may quickly lead to failure of the nozzle. As a result, conventional thrust-vectorable rocket motor nozzles may fail after only one or two consecutive pulses during continuous exposure to a space environment.